*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

a{
    text-decoration: none;
}

html,body{
    font-family: "微软雅黑";
    font-size: 12px;
}


#app{
    width: 1000px;
    height: 200px;
    background-color: orange;
}